New York City is in the midst of a syphilis outbreak and is leading the nation in the number of new infections, officials said yesterday.

In the past two years, infections here have increased threefold, officials said. From 2001 to 2002, there was a 54 percent spike in new cases.

Last year, the Big Apple reported 434 cases.

“New York’s absolute number of cases is tops in the country,” said John Douglas of the Atlanta-based federal Centers for Disease Control.

The city’s rate per 100,000, which is adjusted for population, puts it 20th in the country, Douglas said.

New York clocks in 5.4 infections per every 100,000 residents. The national rate is 2.4.

“Men accounted for 96 percent of our cases . . . The largest increases have been among white men,” said city Assistant Health Commissioner Susan Blank.

She said her department interviewed two-thirds of the patients and discovered that 83 percent of them had gay sex and 61 percent are HIV positive.

Most of the men were Manhattan residents.

Officials said the outlook for this year was bleak.

“The concern for us is that the syphilis outbreak is going to be heralding in the next couple of years increases in HIV locally,” Blank said. He said syphilis rates were rising internationally as well.